Blower for compressed combustible gases



Nov. 28, 1950 H. PFENNINGER 2,532,035

BLOWER FOR COMPRESSED COMBUSTIBLE GASES Filed May 9, 1946 2 Sheets-Sheet 1 pg. [Q I 3 F 1 1 I; a 9 l0 5 Ma/qr Lab nhfb 4 Pack/n l k-u I Nov. 28, 1950 H. PFENNINGER 2,532,035

BLOWER FOR COMPRESSED COMBUSTIBLE GASES Filed May 9, 1946 2 Sheets-Sheet 2 Patented Nov. 28, 1950 UNITED srarss; P TE GFFICE GASES BIQoWEit ooMPREssEn COMBUSTIBLE Hans Pfenninger, Baden, Switzerland, assignor to Aktiengesellschaft Brown, Boveri & Gie., Baden,

Switzerland Application May 9,1946, scram. 668,387

In Switzerland May 15, 1945 v f .f i8 necessary gasiis lT i id es, because, th laces Cipro.-

1 mass, (01. 230-48) to convey combustible.

duction, 'for instance cokingplants or gas Wells,

frequently are at great distances from theiplaces of s umsti In order. that the. pipe lines shall not be, too large and the conveying work shall remain within, reasonable limits, the gas is first fairl highly compressed-$" about 40-60 kgjomE-and inorderz-that this pressure shall be ;nainta ined, along the pipe line, conveying-- blowers are interposed in the. pipe line at suitable intervals, which compensatethe drop in pressure. Electric motors, petrol or Diesel engines may be used as thesource ofpower and, for conveying large quantities, turbine blowers may beused.

On account of the high speed of revolution labyrinthstufiing boxes only are employed as a rule for these turbine blowers; when they are of good construction, the. gas losses will remain deoidedly 10w spiteof the high pressures, sothat y'a regarded .as unimportant. It ,would seem, however, that hitherto the fact has been overlooked,.that the usual-gas lossesthroughstufling boxes,small as they may appear,

when compared with'thequantitypconveyed in many cases, suffice. to cover. the amount offuel required for driving .the conveying blower. It is therefore proposed accordin to the invention,

to collectv the quantityof gas escaping through the stuffing box of the conveying blower and to use it as fuel forthe driving motor of the conveying' blower That this must be advantageous is obvious. I.

An arrangementfor carrying out the method is characterised, in its simplest .form, by a conveying blower which is driven by means oE an internal combustion engine and has at least one stuffing box connected by a pipe with the internal combustion engine.

When a supercharged motor is used as the driving motor, the gas would first have to becompressed. .The, present invention-can, however, 7

be still, further improved. For, as the gas-in the conveying, pipe is under high pressure, it is,

which is present in any case may be llsdlifilf i stead; however, of using sealing air, the leaking gas may be drawn y suction from the smiling box by means of a suction blower. In most cases, however, itwill suflice, if the suitable" place of the stufiing box be connected with the suction branch of the blower or the suction pipe of the driving motor. The sucked-off gases will thus pass .to the combustion chamber of'the power unit and are thus usefully consumed.

When a'g'as turbine is used as the machine for driving the conveying blower, the gas blower norinally used to deliver gas to the turbine may also be omitted. The stuffing box of the conveying blower willv then be tapped at a pressure corresponding to the pressure in the combustion chamber of the gas turbine; in this way'the gas turbine requires no gas blower, but only an' air In this case as blower for the combustion air. well the compressed combustion air can also be utilised for sealing the stufiing box and thus" all the-stufiing'box gas can be conveyed to the gas turbine. :5

shouldqthe stuffing box loss be greate'r than l the consumption oi the driving motor, the'excess can-housed for other purposes or blown off.

Shouldthe .stufiingbox loss be insufficient, additional gas under pressure can be withdrawn from I the conveying pipe.

As this gas'under pressure is highly compressed, it may pay in certain circumstances to use up its expansion work and not to throttle the but to let itwork in. an expansion'inotor, for'inst'ance an expansion turbine.- Should the pressure gas, be additionallyheated' before expansion by Waste heat of the-mainrnotor, the expansion workjcan be substantially increased. 11 the pressure ratio in thewexpansionturbine be very great, heating the gases before the expansion is even necessary,

so aato avoid anexcessive cooling gasesduring.the expansion. v

The method shall now be more particularly described-with reference to several examples "or arrangements for carrying it into effect.

CiOWnof the In Figure l of the accompanying drawii'igs, I is thesuction side; 2 the'pressure side of the coh-' veying blower 3. 4 is the stuffing box, 5 the tapping point and S the sealing channel. The motor 1 is charged by the charging blower 8 which is driven either by the motor 1 (as shown) or for instance by an exhaust gas turbine. The pipe 9 conveys the compressed air to the mixing valve I 9. Through the pipe H the gas flows from the tapping point 5 of the stuffing box 4 also under pressure to the mixing valve Hi, from where the pipe [2 conveys the mixture to the motor 7.

If the outer part of the stufiing box i, that is the part nearest the place where the shaft emerges, is to be sealed with pressure air, compressed air is conveyed by a pipe 13 to the sealing channel 6.

The motor '1 can also be operated without supercharging, in which case the blower 8 and the pipes 9 and 13 are not required. The sealing by air at 6 can then be effected by a separate sealing blower.

Should the quantity of gas from the stufiing box be insufiicient as fuel for the motor 'I, additional gas can be supplied from the pipe I through a pipe M with a reducing valve 15 to the mixing valve lil.

Figure 2 shows an installation, in which the drive for the conveying blower 3 is supplied by a gas turbine. l is the suction side and 2 the pressure side of the conveying blower 3. =3 is the stuifing box with the tapping channel 5 and the sealing channel 6. The air blower I6 compresses atmospheric air which flows through the pipe Ill and the preheater 13 to the com bustion chamber M. A portion of the air passes through the pipe 13 as sealing air to the channel 6 of the stuffing box t. The gas is conveyed from the tapping channel 5 through the pipe Ii also to the combustion chamber 19. The driving gases flow through the pipe 28 to the gas turbine 2i, where through expansion to atmospheric pressure they perform so much work that the gas turbine 2! drives both the blower it; and the con veying blower 3. The expanded waste gases will then in the preheater 18 give off heat to the pressure air.

Should the stuffing box loss be insufiicient as fuel for the gas turbine, then through the pipe 14 with the reducing valve i 5 additional gas may be conveyed from the pipe 1 into the pipe H.

The preheater I8 can also be omitted, when more importance is attached to simplicity of the installation than to a low fuel consumption.

Figure 3 shows the same installation as Figure 2, but amplified by the expansion turbine 22 for the additional gas. The additional gas is withdrawn from the suction branch I of the conveyin blower 3 through the pipe Ma, is preheated in the preheater 23 by the waste gases and is then expanded in the turbine 22. From there the expanded gas passes through the pipe Mb into the pipe H which conveys the stuffing box as.

Figure 4 shows an installation which also has a gas turbine 2| as the driving motor for the conveying blower. In this case the provision of a separate suction blower is avoided through the part 6 of the stuffing box 4 being connected with the suction branch 24 of the blower 16.

It is thus possible to draw air by suction from the outer part of the stuinng box 4 from the outside inwards to the sealing channel 6 and leaking gas from the inside outwards to the same sealing channel 6 and to convey the mixture to the combustion chamber 19, by conducting it into the suction pipe 24 of the blower I6.

I claim:

1. Apparatus for conveying a combustible gas 4 1 under pressure comprising a conveying blower having an inlet thereto for the gas to be conveyed and an outlet therefrom for said gas, said blower having a stufing box, an internal oombustion engine connected to drive said blower, and a conduit communicating between the interior of said stufiing box at a point at which the gas is at a substantial superatmospheric pressure and said engine.

2. Apparatus as defined in claim 1 in which the internal combustion engine is a gas turbine and the apparatus comprises a blower for delivering gas to said gas turbine, said conduit communicating between said stufiing box at a point at which the gas therein is at a substantial superatmospheric pressure and the inlet of said gas turbine and a second conduit communicating between said stuifing box at a point at which the gas therein is at a lower pressure and the inlet of said blower.

3. Apparatus as defined in claim 2 in which the second conduit communicates between the stuffmg box at a point at which the gas therein is at a lower pressure and the outlet of the blower.

4. Apparatus as defined in claim 2 comprising a second conduit, communicating with the interior of the stufi'ing box at a point at which the gas therein is at a lower superatmospheric pressure than at said first named point; and means for supplying gas under superatmospheric pressure to said second conduit.

5. Apparatus for conveyin a combustible gas under pressure comprising a conveying blower having an inlet thereto for the gas to be conveyed and an outlet therefrom for said gas, said blower having a stufiing box, an internal comoil bustion engine connected to drive said blower, a conduit communicating between the interior of said stufl'ing box at a point at which the gas is at a substantial superatmospheric pressure and said engine, a charger for the internal combustion engine and a second conduit communicating between said charger and said stufiln box at a point at which the gas is at a lower pressure.

6. Apparatus for conveying a combustible gas under pressure comprising a conveying blower having an inlet thereto for the gas to be conveyed and an outlet therefrom for said gas, said blower having a stuffing box, an internal combustion engine connected to drive said blower, a conduit communicating between the interior of said stuffing box at a point at which the gas is at a substantial superatmospheric pressure and said engine, means for creating subatmospheric pressure and a second conduit communicating between said means and said stufiing box at a point at which the gas is at a lower pressure.

HANS PFENNINGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,355,231 Kien Oct. 12, 1920 2,020,456 Cook Nov. 12, 1935 2,139,357 Dahlstrand Dec. 6, 1938 2,231,307 Wallace Feb. 11, 1941 

